ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.

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The Bottom Line

Today the avalanche danger is MODERATE at both Treeline and in the Alpine. Small human triggered wet avalanches are possible on very steep slopes and wind slabs 1-2' deep could be found at elevations above 3500’. Avoid steep slope angles and in general be careful – the snow conditions are relatively poor and also ripe for non-avalanche related injuries.

Show the Complete North American Avalanche Danger Scale

North American Public Avalanche Danger Scale

Avalanche danger is determined by the likelihood, size and distribution of avalanches.

Danger Level

Travel Advice

Likelihood of Avalanches

Avalanche Size and Distribution

5 Extreme

Avoid all avalanche terrain.

Natural and human- triggered avalanches certain.

Large to very large avalanches in many areas.

4 High

Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

Natural avalanches likely; human- triggered avalanches very likely.

Large avalanches in many areas; or very large avalanches in specific areas.

Do you ski or snowmachine in Hatcher Pass? The Hatcher Pass Avalanche Center (HPAC) and the Alaska Avalanche School (AAS) are leading an Observer’s Workshop for backcountry enthusiasts who are interested in submitting snow and avalanche observations to the HPAC. More info can be found by clicking here.

Avalanche Problem 1

In the last 24hours a low-pressure system has brought us very warm temperatures (40’sF) at sea level and rain to 3000’. In Turnagain Pass .5” of water was recorded and double that amount in Girdwood.

It is important to understand that our current snowpack is comprised of large areas of dense supportable snow in the Alpine, but pockets of weaker snow do exist. Triggering a wet loose avalanche requires a steep slope (>40°) and could be larger on sustained slopes. Today this problem will be more likely at mid elevations where there are greater areas of low-density snow.

Expected this type of avalanche to be slow to initiate, meaning they take a little time to gain momentum. Use caution if you choose to ski/ride in steep terrain today. This kind of avalanche problem is wet and heavy and can easily grab your ski/board and pull you down.

Today light precipitation (0.1”) is expected throughout the day and rainline may decrease to 1000’. This is not enough precipitation to increase the likelihood of natural avalanches.

Avalanche Problem 2

At higher elevations, above 3500’, where snow has accumulated there is potential for wind slabs. Yesterday ridgetop winds were from the East and averaged 30mph. Avoid wind loaded leeward slopes if you venture above 3500’. Small pockets 1-2’ deep could be found on leeward sides of ridges and along terrain features such as gullies.

Luckily today with marginal weather and poor surface conditions this terrain will not be very attractive to ski/ride. In fact your day might be better spent tuning your skis with a warm colored wax and saving gas money in hopes of improved conditions in the coming days.

Additional Concern

We have been tracking several types of buried weak layers over the last three weeks. Recent loading in the last 24hours in the form of rain combined with warm temperatures could be adding additional stress. A persistent slab is more likely to be triggered on very steep slopes and in places with a generally thinner snowpack like the Summit Lake area. This problem is becoming a bit of an outlier, but we do feel it is worth keeping in the back of your mind if you are thinking about venturing onto sustained steep slopes.

Mountain Weather

Yesterday a warm low-pressure system brought us temperatures into the 40’s F at sea level and rainline was near 3000’. Ridgetop winds were predominantly from the East averaging 30mph and .5 inches of rain was measured in Turnagain Pass and just over 1” in Girdwood.

Today warm temperatures and very light rain will persist throughout the day. Rainline may creep down to about 1000’, but only a trace of new snow is expected to fall at higher elevations. Ridgetop winds are expected to be 20- 40mph from the East.

Warm temperatures and light precipitation will continue into the weekend with our next chance for cooler temperatures on Saturday night. Winds should be light to moderate from the East.

PRECIPITATION 24-hour data (6am - 6am)

Temp Avg (F)

Snow (in)

Water (in)

Snow Depth (in)

Center Ridge (1880')

38

0

0.5

30

Summit Lake (1400')

37

0

0.5

6

Alyeska Mid (1700')

37

0

1.17

23

RIDGETOP 24-hour data (6am - 6am)

Temp Avg (F)

Wind Dir

Wind Avg (mph)

Wind Gust (mph)

Sunburst (3812')

31

E

29

64

Seattle Ridge(2400')

33

ENE

26

58

This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.

(Updated: Mar 20, 2019 )

AREA

STATUS

WEATHER AND RIDING CONDITIONS

Glacier District

Johnson Pass:

Open

Placer River:

Closed

Closed as of 3.20.19 due to lack of snow.

Skookum Drainage:

Closed

Placer access closed as of 3.20.19 due to lack of snow.

Turnagain Pass:

Open

Twentymile:

Closed

Closed as of 3.20.19 due to lack of snow.

Seward District

Carter Lake:

Open

Lost Lake Trail:

Open

Please stay on trail to avoid resource damage through forested areas.

Primrose Trail:

Open

Please stay on trail to avoid resource damage through forested areas.

Resurrection Pass Trail:

Closed

Closed for the 2018/19 season. Next season will be open to motorized use.

Chance of Avalanches

This graphic depicts how likely you are to trigger avalanches or encounter natural avalanches while traveling on avalanche prone slopes. Unlikely means that few avalanches could be triggered in avalanche terrain and natural avalanches are not expected. The chance of triggering or observing avalanches increases as we move up the scale. Certain means that humans will be able to trigger avalanches on many slopes, and natural avalanches should be expected.

Size of Avalanches

This graphic depicts the potential size and destructive force of expected avalanches. Small avalanches are not large enough to bury humans and are relatively harmless unless they carry people over cliffs or through trees or rocks. Moving up the scale, avalanches become large enough to bury, injure, or kill people, large enough to bury or destroy vehicles and break a few trees, and large enough to destroy railway cars, buildings, or a substantial amount of forest. Historic avalanches are massive events capable of destroying villages and gouging or altering the landscape.

Chance of Avalanches

This graphic depicts how likely you are to trigger avalanches or encounter natural avalanches while traveling on avalanche prone slopes. Unlikely means that few avalanches could be triggered in avalanche terrain and natural avalanches are not expected. The chance of triggering or observing avalanches increases as we move up the scale. Certain means that humans will be able to trigger avalanches on many slopes, and natural avalanches should be expected.

Size of Avalanches

This graphic depicts the potential size and destructive force of expected avalanches. Small avalanches are not large enough to bury humans and are relatively harmless unless they carry people over cliffs or through trees or rocks. Moving up the scale, avalanches become large enough to bury, injure, or kill people, large enough to bury or destroy vehicles and break a few trees, and large enough to destroy railway cars, buildings, or a substantial amount of forest. Historic avalanches are massive events capable of destroying villages and gouging or altering the landscape.

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.
This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.